hmm haven't yet cleared a map of corruption yet, also as you destroy corruption, enemy spawn as it decays, also I think only lamps can push back decay, and decay doesn't recede if cut off, it can live independently

Originally posted by StrikeLaserClaw:

hmm haven't yet cleared a map of corruption yet, also as you destroy corruption, enemy spawn as it decays, also I think only lamps can push back decay, and decay doesn't recede if cut off, it can live independently

Thank you for your answer, but in the last fight the lamps take a very very long time to destroy the corrupted spots and the monsters seem to come from everywhere. I will fight back as long I can do it

Nothing comes from "outside the map"; check the overlays and click on the one that says something like "Corrupted Tiles'--that will specifically highlight the ones that drones and monsters can still spawn out of, even if they're underwater. Also, drones that spawn from underwater corruption will dig out dry land.